BULLETIN  OF 

ILLINOIS  COAL  MINING  INVESTIGATIONS 

COOPERATIVE  AGREEMENT 

Issued  bi-monthly 
VOL.  I  November,  1914  No.  5 

State  Geological  Survey 

Department  of  Mining  Engineering,  University  of  Illinois 

U.  S.  Bureau  of  Mines 


BULLETIN  8 

Coal  Mining  Practice 
District  VI 


BY 
S.  O.  ANDROS 

Field  work  by  S.  O.  Andros  and  R.  Y.  Williams 


Published  by 

University  of  Illinois 

Urbana,  Illinois 


(Entered  at  secqndclasi  matter,  June  1,  1914,  at  the  postofficc  at  Urbana,  Illinois,  under 
the  Act  of  August  24,  1912.) 


The  Forty-seventh  General  Assembly  of  the  State  of  Illinois, 
with  a  view  of  conserving  the  lives  of  the  mine  workers  and  the 
mineral  resources  of  the  State,  authorized  an  investigation  of  the 
coal  resources  and  mining  practices  of  Illinois  by  the  Department  of 
Mining  Engineering  of  the  University  of  Illinois  and  the  State 
Geological  Survey  in  co-operation  with  the  United  States  Bureau  of 
Mines.  A  co-operative  agreement  was  approved  by  the  Secretary  of 
the  Interior  and  by  representatives  of  the  State  of  Illinois. 

The  direction  of  this  investigation  is  vested  in  the  Director  of 
the  United  States  Bureau  of  Mines,  the  Director  of  the  State 
Geological  Survey,  and  the  Head  of  the  Department  of  Mining 
Engineering,  University  of  Illinois,  who  jointly  determine  the 
methods  to  be  employed  in  the  conduct  of  the  work  and  exercise 
general  editorial  supervision  over  the  publication  of  the  results,  but 
each  party  to  the  agreement  directs  the  work  of  its  agents  in  carrying 
on  the  investigation  thus  mutually  agreed  on. 

The  reports  of  the  investigation  are  issued  in  the  form  of  bul- 
letins, either  by  the  State  Geological  Survey,  the  Department  of 
Mining  Engineering,  University  of  Illinois,  or  the  United  States 
Bureau  of  Mines.  For  copies  of  the  bulletins  issued  by  the  State 
and  for  information  about  the  work,  address  Coal  Mining  Investiga- 
tions, University  of  Illinois,  Urbana,  111.  For  bulletins  issued  by 
the  United  States  Bureau  of  Mines,  address  Director,  United  States 
Bureau  of  Mines,  Washington,  D.  C. 


'LLINOIS  STATE  GEOLOGICAL  SURVEY 


3  3051  00006  3671 


ILLINOIS 

COAL  MINING  INVESTIGATIONS 

COOPERATIVE  AGREEMENT 


State  Geological  Survey 

Department  of  Mining  Engineering,  University  of  Illinois 

U,  S.  Bureau  of  Mines 


BULLETIN  8 

Coal  Mining  Practice 

IN 

District  VI 


BY 
S.  O.  ANDROS 

Field  work  by  S.  O.  Andros  and  R.  Y.  Williams 


Urbana 

University  of  Illinois 

1914 


1914 


CONTENTS 

Page 

Introduction      7 

Description    of   coal   bed 10 

Mining     practice 1] 

Ventilation    21 

Blasting      32 

Timbering 37 

Haulage      41 

Hoisting     44 

Preparation   of   coal 46 


Fig. 

1. 

Fig. 

2. 

Fig. 

3. 

Fig. 

4. 

Fig. 

5. 

Fig. 

6. 

Fig. 

7. 

Fig. 

8. 

Fig. 

9. 

Fig. 

10 

Fig. 

11. 

Fig. 

12. 

Fig. 

13. 

Fig. 

14. 

Fig. 

15. 

Fig. 

16. 

Fig. 

17. 

Fig. 

18. 

Fig. 

19. 

Fig. 

20. 

Fig. 

21. 

Fig. 

22. 

Fig. 

23. 

Fig. 

24. 

Fig. 

25. 

Fig. 

26. 

Fig. 

27. 

Fig. 

28. 

Fig. 

29. 

Fig. 

30. 

ILLUSTRATIONS 

Page 

Map  showing  area   (shaded)   of  District  VI Frontispiece 

Stripping  near  Duquoin  where  overburden  is  removed  with  horse-scrapers 12 

Plan  of  room-and-pillar  mine 13 

Face  of  room  which  has  been  passed  over  by  squeeze 15 

Surface   subsidence    caused   by    squeeze 1G 

Method    of   drawing   pillars IT 

Pump  room  near  shaft  bottom 20 

Metal-lath   stopping  replaced  after   failure  by  concrete  monolith 21 

Leaky  gob  stopping 22 

Stopping  built  of  old  ties  and  fine  gob 23 

Mud-plastered  gob  stopping  covered  with  wood-fibre 2  4 

Board   stopping   having   cracks   plastered   with   wood-fibre 2.3 

Efficient  brick  stopping 26 

Retaining  wall  of  concrete  having  aggregate  of  sand  and  slack  coal 20 

Concrete     overcast 27 

Steel  hay  car  and  concrete  hay  room 29 

Typical    underground    stable 31 

Method  of  placing  holes  when  black  powder  is  used 34 

Method  of  placing  holes  when  permissible  explosives  are  used 35 

Method  of  shooting  with  two  benches 36 

Solid  concrete  pier  at  branch 37 

Cog  timbering  at  parting 38 

Shaft  bottom  with  roof  supported  by  steel  I-beams  set  on  concrete  walls 3S 

Typical   room   propping 39 

Mouth   of   concrete-lined   shaft 39 

Underground    machine    shop 41 

Automatic    caging   device 45 

Fireproof   steel    tipple 47 

Frame   surface   plant 4S 

Interior   of   wash-house. 49 


TABLES 

No.  Page 

1.  General  data  by  counties  for  the  year  ended  June  30,  1912 S 

2.  Comparative    statistics    for    District    VI    and    the    State   for   the   year   ended   June   30, 

1912     9 

3.  Average  analyses  of  No.   6  coal  in  Districts  VI  and  VI I 11 

4.  Dimensions  of  workings  in  feet 14 

5.  Per  capita  production  of  coal 18 

6.  Causes  of  accidents  to  employees 19 

7.  Pressure  developed  by  dust  of  face  samples  in  explosibility  apparatus 28 

S.     Ventilating    equipment 30 

9.     Blasting    data 33 

10.  Data   concerning   props   in   rooms 40 

11.  Ton  mileage  of  locomotives 42 

12.  Underground     haulage 43 

1 3.  Hoisting    data 45 

1 4.  Preparation  of  coal  for  market 48 

15;      Surface   plant   equipment 49 


Fig.  1.     Map  Showing  Area   (Shaded)  of  District  VI 


COAL  MINING  PRACTICE  IN  DISTRICT  VI 

By  S.  O.  ANDROS 

Field   Work  by    S.   O.   Andros  and   R.   Y.   Williams 


INTRODUCTION 

District  VI  of  the  Illinois  Coal  Mining  Investigations,  as  shown 
in  Hg.  1,  includes  all  mines  operating  in  coal  bed  6  east  of  the 
Duquoin  anticline  in  Franklin,  Jackson,  Perry,  and  Williamson 
Counties. 

A  detailed  description  of  the  districts  into  which  the  state  has 
been  divided  and  the  method  of  collecting  the  data  upon  which  this 
bulletin  is  based  are  contained  in  Bulletin  1,  "A  Preliminary  Report 
on  Organization  and  Method  of  Investigations." 

This  district,  with  a  production  during  the  year  ended  June 
30,  1912,  of  12,029,450  tons,  20.8  per  cent  of  the  total  production 
of  the  State,  is  one  of  the  most  important  of  the  Illinois  districts, 
and  its  undeveloped  coal  resources  are  so  great  that  it  doubtless  will 
become  the  most  important.  In  the  year  ended  June  30,  1912,  there 
were  operating  in  the  district  78  mines,  60  shipping  and  18  local, 
employing  14,562  men  on  an  average  of  166  days. 

Mining  machines  undercut  6,379,704  tons  of  coal,  53.3  per  cent 
of  the  output  of  the  district.  The  use  of  undercutting  machines  has 
made  possible  a  high  daily  production  for  the  face  workers,  that  is, 
miners,  loaders,  and  machine  men.  In  District  VI  face  workers 
in  shipping  mines  produced  an  average  of  7.6  tons  daily  as  com- 
pared to  an  average  of  5.9  tons  per  face  worker  in  the  mines  of  all 
other  districts  in  the  State.  There  is,  however,  a  greater  amount 
of  explosives  used  than  seems  warranted  with  so  large  a  proportion 
of  undercut  coal.  In  the  mines  of  this  district  there  is  burned  18.0 
per  cent  of  all  the  black  powder  used  for  blasting  coal  in  Illinois: 
and  in  addition  during  the  year  ended  June  30,  1912,  236,367 
pounds  of  permissible  explosives  were  used — 99.5  per  cent  of  all 
permissibles  sold  in  the  State.  Table  1  gives  general  data  for  the 
district  and  Table  2  comparative  statistics  for  District  VI  and  the 
State  for  the  year  ended  June  30,  1912. 


COAL    MINING    INVESTIGATIONS 


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MINING     PRACTICE 


The  operators  of  this  district  allowed  free  access  to  their  mines, 
and  did  everything  else  possible  to  assist  in  the  collection  of  data. 
The  superintendents  and  mine  managers  who  acompanied  the  en- 
gineers through  the  mines  gave  all  information  requested.     Grateful 


acknowledgments  are  made  to  them. 


Table  2. — Comparative  statistics  for  District  VI  and  the  State  for 
the  year  ended  June  30,  1912  a 


District 


Total  production 

No.  tons  mined  by  machine 

Average  daily  tonnage 

Kegs  of  powder  used  in  blasting  coal 

Pounds  ofp  ermissible  explosives  used  in  blast 

ing  coal 

Average  no.  days  of  active  operation 

Total  no.  employees 

No.  days  work  performed 

No.  surface  employees 

No.  underground  employees 

Average  no.  face  workers  (miners,  loaders,  and 

machine  men)1' 

No.  underground  employees  per  each  surface 

employee 

No.  tons  mined  per  day  per  employee 

No.  tons  mined  per  day  per  surface  employee 
No.  tons  mined  per  day  per  underground  em- 
ployee   

No.  tons  mined  per  day  per  face  worker b    .  . 
No.  fatal  accidents 

Per  cent  from  falling  rock  or  coal 

Per  cent  from  pit  cars 

Per  cent  from  use  of  explosives 

Per  cent  from  gas  explosions 

Per  cent  from  undercutting  machines  .... 

No.  fatal  accidents  per  1000  employees 

No.  tons  mined  to  each  life  lost 

No.  non-fatal  accidents 

Per  cent  from  falling  rock  or  coal 

Per  cent  from  pit  cars 

Per  cent  from  use  of  explosives 

Per  cent  from  gas  explosions 

Per  cent  from  undercutting  machines  .... 
No.  non-fatal  accidents  per  1000  employees. 
No.  tons  mined  to  each  man  injured 


12,029,450 

6,379,704 

72,461 

236,367 

326,925 

166 

14,562 

2,417,292 

1,436 

13,126 

10,040 

9.2 
5.0 

50.4 

5.5 

7  6 

38 

52.7 

23.7 

10.5 

2.6 

0.0 

2.6 

316,561 

126 

33.4 

27.8 

1.6 

7.2 

3.2 

11.5 

95,472 


State 


57,514,240 

25,550,019 

359,464 

1,313,448 

328,075 

160 

79,411 

12,705,760 

7,049 

72,362 

53,318 

10.3 

1.5 
50.9 

4.9 

6.1 

180 

51    I 

18.8 

7.2 

6.9 

0.0 

2  3 

3 19.5 2  I 

800 

45.5 

26  3 

2.6 

2.9 

2.8 

10.1 

7  1 ,893 


Per  cent 


20.9 
24.9 


IS 


a  Compiled  from  Thirty-first  Annual  Coal  Report  of  Illinois. 
1)  Shipping  mines  only. 


Particularly  valuable  aid  was  rendered  by  M  i\  George  A.  Pow 
ers,  Superintendent,  Hart-Williams  Coal  Company;  Mr.  Roberl 
Forester,  Superintendent,  Paradise  Coal  and  Coke  Company;  Mr. 
J.  P.  Rend,  Vice-President,  and  Mr.  J.  L.  Ohle,  Superintendent,  W. 
P.  Rend  Collieries  Company;   Mr.   K.  M.    Medill,  Superintendent, 


10  COAL    MINING    INVESTIGATIONS 

Dering  Coal  Company;  Mr.  George  L.  Morgan,  State  Mine  Inspec- 
tor; and  Mr.  Oscar  Cartlidgc,  Manager,  Illinois  Mine  Rescue 
Stations. 

DESCRIPTION  OF  COAL  BED 

Bed  6  of  the  Illinois  State  Geological  Survey  correlation  in  Dis- 
trict VI  is  described  as  follows  by  E.  W.  Shaw  and  T.  E.  Savage 
in  Folio  No.  185  published  by  the  U.  S.  Geological  Survey: 

"The  bed  is  uniformly  thick,  ranging  from  7^  to  14  feet  and 
averaging  9  feet  5  inches  in  130  borings.  The  coal  is  shining  black, 
commonly  banded,  and  on  close  inspection  appears  laminated  with 
alternating  bright  and  dull  lines.  A  'blue  band'  or  dirt  band, 
found  almost  everywhere  18  to  30  inches  above  the  floor,  generally 
consists  of  bone  or  shaly  coal  or  of  gray  shale.  Its  thickness  varies 
from  one-half  to  2-J-  inches,  with  an  average  of  If  inches. 

"A  clean  persistent  parting  of  mother  coal  lies  14  to  24  inches 
below  the  top  of  the  bed,  and  a  second  parting  generally  appears  5 
to  8  inches  lower  down.  Above  the  upper  parting  the  coal  is  in 
layers  3  to  G  inches  thick,  with  partings  of  mother  coal  between 
them.  Local  lenses  of  mother  coal,  6  inches  to  5  feet  in  length  and 
1  inch  to  4  inches  thick,  are  common  in  the  upper  third  of  the  bed. 
Small  pyrite  lenses  and  streaks  of  bone,  varying  from  a  few  inches 
to  a  foot  or  more  in  length  and  from  one-fourth  inch  to  1  inch  in 
thickness,  are  found  here  and  there  in  the  middle  portion  of  the 
bed,  a  short  distance  above  the  'blue  band.'  In  the  middle  and 
lower  parts  of  the  bed  the  lamination  is  less  distinct  but  the  bedding 
is  still  evident. 

" Above  the  coal  there  is  a  bed  of  gray,  impure  shale,  15  to  110 
feet  thick,  the  lower  part  of  which  generally  contains  a  great  number 
of  plant  impressions.  This  shale  does  not  stand  well  when  the  coal 
is  removed,  and  for  this  reason  the  18  to  30  (60)1  inch  zone  of  coal 
above  the  charcoal  parting  is  usually  left  for  a  roof  until  the  rooms 
are  mined  out,  after  which  it  may  be  taken  down.  The  clay  beneath 
the  coal  is  hard  and  generally  thin,  ranging  in  thickness  from  4 
inches  to  8  feet.  It  is  generally  underlain  by  a  limestone.  Some 
rock  rolls  occur  at  the  top,  the  larger  ones  extending  down  into  the 
coal  2  to  3  feet." 

In  addition  to  the  structural  features  mentioned  above,  faults 
of  considerable  magnitude  for  Illinois  have  been  discovered  in 
mining.  One  block  fault  in  which  the  block  has  dropped  50  feet  has 
been  recorded  by  F.  H.  Kay  of  the  State  Geological  Survey. 

].     Author. 


MINING     PRACTICE 


11 


A  detailed  report  on  the  geology  of  this  district  is  in  preparation 
and  will  he  published  later  as  a  sej^arate  bulletin. 

Locally  considerable  explosive  gas  (methane)  is  found  in  mines 
working*  in  this  bed,  especially  in  sections  working  to  the  rise.  The 
quality  of  the  coal  in  this  district  is  better  than  that  of  ^o.  6  coal 
in  District  VII  west  of  the  Duquoin  anticline.     (Table  3.) 

Table  3. — Average  analyses  of  No.  6  coal  in  Districts  VI  and  YIP 


Average 

thickness 

of  coal  in  feet 

'a 

a 

a 

m 

6 

Proximate  analysis  of  coal  1st;  "as  ree'd"  with 
total  moisture.    2nd;  "Dry"  or  moisture  free 

District 

w 

'o 

^     V-i 

>  6 

TJ   o 

E  5 

en 

< 

u 

pq 

Unit 
coal 
B.  t.  u. 

VI  (East  of  Duquoin 
anticline) 

9 

58 

9.21 

Dry 

34.00 
37.45 

48.08 
52.96 

8.71 
9.59 

1.53 
1.68 

11825 
13025 

' 14585 

VII  (West  of  Du- 
quoin anticline) 


70 


12.56 
Dry 


38.05 
43.52 


39.06 
44.67 


10.33 
11.81 


4.01 
4.59 


98-^8 
12406 


14S77 


Analysis  made  by  J.  M.  Lindgren  und.T  direction  of  Prof.  S.  \V.  Parr. 


In  a  few  mines  where  cleat  in  the  coal  is  developed  the  roof  is 
jointed  and  can  be  easily  supported  only  in  rooms  driven  east  and 
west. 

In  some  mines  there  are  small  areas  in  which  the  cap  rock  is 
lacking.  If  the  coal  is  removed  under  these  areas  the  roof  caves 
filling  the  entries  with  clay  and  sand  and  causing  subsidence. 


AI I  X  I  X(i  PKACTICE 

Bed  6  outcrops  along  the  Duquoin  anticline  bu1  dips  sharply 
to  the  east  reaching  a  depth  of  726  fee!  al  Sesser.  A  general  uplift 
has  brought  it  to  the  surface  along  an  east-west  line  extending 
through  Carterville  to  Marion  and  along  a  southeasl  line  from 
Marion  to  the  boundary  of  the  district.  East  of  the  area  affected 
by  the  Duquoin  anticline  the  bed  has  a  pronounced  dip  to  the  north. 
Along  the  outcrop  line  there  are  3  slopes  and  -\  strippings  bul  the 
steep  dip  of  the  bed  leaves  only  a  small  acreage  with  thin  cover  and 
the  remaining  72  openings  in  the  district  are  shafts.  (  Fig.  2  shows 
a  shallow  stripping  near  Duquoin  at  which  the  overburden  is  re- 
moved by  horse-scrapers.)  In  all  closed  workings  either  the  double- 
entry  room-and-pillar  or  the  panel  system  is  w^>d.  Fig,  ;]  shows 
a  plan  of  a  room-and-pillar  mine. 


12  COAL    MINING    INVESTIGATIONS 

In  a  few  mines  an  east-west  cleat  in  the  coal  is  so  pronounced 
that  top  coal  will  not  stay  up  if  rooms  are  driven  north  or  south. 
In  one  mine  formerly  operating  on  panels,  which  made  necessary 
the  driving  of  rooms  north  and  south,  the  system  has  been  changed 
to  unmodified  room-and-pillar  in  order  that  rooms  may  have  an 
east-west  direction. 

Ribs  are  hand-sheared  in  all  the  entries  in  one  mine.  In  an- 
other, all  entries  are  driven  on  two  benches.  The  upper  bench,  4 
feet  high,  is  carried  6  feet  ahead  of  the  lower  bench,  which  is  3  feet 
high;  in  an  18-foot  entry  a  cut  wide  enough  for  a  man  to  work  in 
is  hand-sheared  6  feet  from  the  rib,  and  extends  from  the  top  coal 


Fig.    2.     Stripping   Near   Duquoin   Where    Overburden    Is   Removed   With   Horse-Scrapers 

to  the  lower  bench.  It  is  claimed  that  this  method  of  entry  driving 
is  faster  than  under-cutting  with  machines.  In  another  mine,  rooms 
but  not  entries  are  driven  on  two  benches. 

In  an  attempt  to  shorten  the  haul  at  one  mine,  pairs  of  cross 
entries  are  driven  600  feet  apart.  Rooms  are  turned  off  each  entry 
of  a  pair,  but  are  not  advanced  at  an  equal  rate  on  both  sides.  Those 
whose  direction  is  toward  the  hoisting-shaft  are  stopped  when  they 
have  been  driven  100  feet.  Those  whose  direction  is  away  from  the 
shaft  are  driven  500  feet  to  hole  through  into  the  rooms  100  feet  long. 

The  immediate  roof  overlying  the  coal  falls  in  slabs  after  short 
exposure  to  the  air  and  top  coal  is  usually  left  to  protect  it,  but 
the  cap  rock  is  a  tough  coherent  shale  which  does  not  break  easily. 
The  first  mines  opened  in  the  district  had  widths  of  rooms  and 
pillars  unsuitable  for  this  tough  cap  rock.     New  mines  as  they  were 


MINING    PRACTICE 


13 


opened  adopted  the  dimensions  of  the  older  mines  and  a  great  waste 
has  resulted  through  the  loss  of  pillar  coal.  Table  4  gives  dimen- 
sions of  workings  at  the  mines  examined.  It  will  never  be  possible 
in  this  district  to  draw  any  considerable  portion  of  the  pillars  where 


Fie.   3.     Plan   of   Room-and-Pillar  Mine 


rooms  20  to  29  feet  wide  are  driven  with  narrow  room  pillars.  Fear 
of  yardage  charges  has  been  an  important  factor  in  maintaining  the 
present  improper  dimensions.  To  work  properly  and  to  make  the 
greatest  possible  extraction  of  the  bed  all  advance  work   should   be 


14 


COAL     MIXING     INVESTIGATIONS 


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MINING    PRACTICE  15 

driven  narrow  leaving  room-pillars  at  least  40  feet  wide  and  better 
GO.  Even  where  rooms  are  20  feet  wide  to  avoid  yardage  charges 
it  will  be  possible  to  draw  pillars,  providing  the  rooms  are  driven 
on  at  least  80-foot  centers  and  especially  if  a  proper  break  line  is 
observed.  With  these  dimensions  rooms  can  be  driven  up  without 
bringing  on  a  squeeze.  At  least  25  per  cent  more  of  the  bed  would 
be  gained  and  operating  expenses  would  be  reduced  with  a  better 
system  of  mining.  The  present  extraction  as  determined  from  state- 
ments furnished  by  the  operators  for  tons  gained  per  acre  averages 
56  per  cent. 

Attempts   to   increase   extraction  by  changing  from   room-and- 


Fig.    4.     Face  of  Room   Which   Has   Been   Passed  Over  by  Squeeze. 

pillar  work  to  panel  have  been  generally  unsuccessful  because  room 
pillar  widths  have  been  insufficient. 

With  present  dimensions  when  rooms  have  been  driven  200  to 
300  feet  there  is  a  large  area  of  unsupported  cap  rock.  If  an  attempt 
is  made  to  draw  pillars  under  such  conditions  a  squeeze  is  usually 
started  which  often  rides  over  room  and  entry  pillars  and  sometimes 
affects  a  large  acreage.  In  one  mine  85  acres  were  squeezed;  in 
another,  80.  There  have  been  from  one  to  six  squeezes  in  each  of 
13  of  the  mines  examined.  Attempts  to  stop  them  have  seldom 
been  successful.  In  one  mine  in  which  they  advance  slowly,  enough 
pillars  are  drawn  ahead  of  the  squeeze  to  cause  a  break;  the  roof 
weight  is  relieved  and  the  squeeze  checked.  In  many  mines  where 
rooms   are  wide   and  room  pillars  narrow,   squeezes  travel   rapidly 


16 


COAL     MINING    INVESTIGATIONS 


and  there  is  not  sufficient  time  to  draw  pillars.  Cog  building  and 
shooting  the  roof  have  often  been  resorted  to,  in  one  instance  at  a 
cost  of  $2,000.  but  they  seldom  check  a  squeeze,  which  may  con- 
tinue till  a  fault  or  barrier  pillar  is  reached.  In  one  mine  operating 
on  the  room-and-pillar  system  every  tenth  room  along  the  cross  entries 
is  omitted,  leaving  a  pillar  49  feet  wide  to  check  possible  squeezes. 
Another  cause  of  squeezes  is  room-pillar  gouging  on  the  advance 
working.  Frequently  after  the  first  crosscut  is  reached  in  driving 
rooms  the  pillar  is  gouged,  sometimes  to  the  extent  that  the  pillar 
between  rooms  is  broken  through.    In  one  mine  a  squeeze  was  brought 

! 


*& , 


Fig.    5.      Surface    Subsidence   Caused   by    Squeeze    (Photo   by   R.    Y.   Williams) 

on  by  turning  rooms  off  the  main  air-course.     Fig.  4  shows  a  room 
which  has  been  passed  over  by  a  squeeze. 

Squeezes  in  comparatively  shallow  mines  in  which  beds  as  thick 
as  No.  6  are  worked  cause  surface  subsidence.  In  this  district  the 
surface  has  subsided  over  certain  sections  of  some  shallow  mines 
so  as  to  outline  plainly  the  rooms  in  the  workings  below.  Subsidence 
is  usually  but  not  always  gradual.  It  may  take  place  rapidly.  With- 
in 36  hours  after  one  squeeze  the  surface  subsided  4  feet  over  an 
area  of  ten  acres.  Fig.  5  shows  a  water-filled  depression  caused  by 
a  mine  squeeze.  Houses  have  sometimes  been  damaged  and  fences 
and  sidewalks  broken  as  the  surface  settled.     In  several  mines  the 


25' 


MINING    PRACTICE  17 

cap  rock  over  the  coal  is  missing  in  some  places,  and  where  the  coal 
is  removed  clay  and  sand  break  through  into  the  rooms  or  entries 
and  sinkholes  appear  on  the  surface. 

In  four  of  the  mines  examined  no  pillar  drawing  is  done,  but 
all  the  coal  hoisted  is  gained  during  the  advance.  In  the  other  mines 
an  attempt  is  made  to  draw  pillars  and  pull  top  coal.  It  is  doubtful 
if  more  than  5  to  10  per  cent  of  the  top  coal  is  recovered.  It  is 
usually  pulled  before  pillars  are  drawn.  At  one  mine  a  fairly  good 
recovery  of  top  coal  is  made  after  rooms  are  driven  up  by  making  a 
cut  in  it  12  inches  wide  across  the  room  at  the  face  and  a  cut  5  feet 
long  along  each  rib  beginning  at  the  face.  Props  under  the  block 
of  top  coal  thus  cut  out  are  then  pulled  and  the  coal  falls.     After  this 

:♦: 

(a)  (b)  (c)  (d) 

Fig.    G.      Method    of    Drawing    Pillars 

block  has  fallen  the  cuts  along  the  ribs  arc  extended  5  feel  further; 
the  props  are  pulled  under  this  second  block  letting  the  coal  come 
down  and  this  procedure  is  continued  as  far  as  possible  along  the 
room.  In  this  mine  about  one-half  of  the  top  coal  in  the  rooms  is 
thus  recovered. 

The  most  common  methods  of  gaining  pillar  coal  are:  (1)  'Fak- 
ing a  5-foot  slab  from  each  rib,  and  (2)  making  a  cut  about  IS  feet 
wide  through  the  pillar  half-way  between  the  crosscuts  required  by 
law.  The  first  method  seems  to  he  productive  of  squeezes,  inasmuch 
as  the  span  of  unsupported  roof  is  widened  by  slabbing  the  pillars. 
The  second  method  does  not,  make  a  sufficient  recovery.  A  more 
elaborate  but  seldom  used  method  is  shown  in  fig.  (>.  In  this  sketch 
"a"  shows  the  pillar  between  two  crosscuts;  "b,"  the  first  cut  through 
the  pillar;  "c,"  the  second  step  in  drawing;  and  "d,"  the  pillar  after 
drawing  is  completed. 

Room-stumps,  if  recovered,  are  not  drawn  till  all  rooms  on  the 
entry  have  been  driven  up  and  all  room  pillars  drawn. 


COAL     MINING    INVESTIGATIONS 


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MINING    PRACTICE 


10 


The  dimensions  of  room  necks  and  the  methods  of  widening 
them  to  full  room  width  vary,  and  in  a  general  way  depend  upon 
roof  conditions  and  whether  top  coal  is  left  up.  Room  neck  widths 
vary  from  9  to  20  feet  and  lengths  from  6  to  24  feet.  Where  room 
pillars  are  not  to  be  drawn  the  neck  is  sometimes  widened  on  both 
sides  at  an  angle  either  of  4-5  or  of  90  degrees,  and  the  track  is  laid 
in  the  center  of  the  room.  When  pillars  are  to  be  drawn,  one  side 
of  the  neck  in  some  mines  is  continued  forming  the  room  rib,  and 
widening  is  done  altogether  on  the  other  side  at  an  angle  varying 
from  45  to  90  degrees,  the  track  being  laid  close  to  the  straight  rib. 
In  other  mines,  one  side  is  widened  at  an  angle  of  90  degrees  for  a 

Table  6. — Causes  of  accidents  to  employees 


Per  cent 

District  VI 

All  other  Illinois 
districts  combined 

Causes  of  fatal  accidents 

Fall  of  rock  or  coal 

Pit  cars 

Use  of  explosives 

Gas  explosions 

52.7 

23.7 

10.5 

2.6 

0.0 

33  4 

27.8 
1.6 

7.2 
3.2 

54.9 

17.0 

6.3 

Undercutting  machines 

Causes  of  non-fatal  accidents 

Fall  of  rock  or  coal 

Pit  cars 

Use  of  explosives 

Gas  explosions 

0.0 

47.2 
25.9 

2.7 
2  1 

Undercutting  machines 

2.7 

distance  of  4  to  9  feet,  and  the  remaining  widening  is  done  on  the 
other  side  at  an  angle  of  45  degrees.  The  total  distance  from  the 
entry  to  the  point  where  full  room  width  is  reached  varies  from  15 
to  45  feet. 

Crosscuts  in  room  pillars  vary  in  width  from  8  to  22  feet. 

The  per  capita  production  of  coal  is  high  for  this  district  as 
compared  with  all  other  districts  combined,  the  ratio  being  5.0  to  4.4. 
The  high  percentage  of  undercut  coal  in  District  VI  and  the  thick- 
ness of  the  bed  are  factors  of  this  high  production.  Face  workers 
average  7.6  tons  daily  as  compared  with  5.9  tons  in  all  other  dis- 
tricts combined.  Table  5  compares  items  of  daily  production  for 
each  mine  examined  for  the  district  and  for  the  State. 

The  number  of  fatal  accidents  compared  with  those  in  the  State 
as  a  whole  is  proportional  to  the  coal  production  but  the  record  of 


20 


COAL     MINING     INVESTIGATIONS 


the  district  for  non-fatal  accidents  is  better  than  that  of  the  remainder 
of  the  State.  An  analysis  of  the  causes  of  accidents  (Table  6)  shows 
that  a  smaller  per  cent  is  caused  by  falls  of  rock  or  coal  than  in  the 
remainder  of  the  State,  and  a  larger  per  cent  from  pit  cars,  dne 
probably  to  piling  gob  alongside  the  track  and  to  the  very  large  cars 
used  in  the  district. 

Water  interferes  very  little  with  mining  operations.  The  larg- 
est amount  pumped  daily  at  any  mine  is  about  200,000  gallons. 
Often  the  only  source  of  water  is  the  hoisting  and  air-shafts.  In  a 
few  mines  considerable  water  is  found  at  the  faces  of  rooms.  In 
those  lying  at  a  depth  of  less  than  200  feet,  breaks  to  the  surface 


Fig.    7.      Pump    Room    Near    Shaft    Bottom 

admit  water  into  the  entries,  but  these  breaks  are  not  frequent.  At 
some  mines  water  collects  in  swamps  in  entries.  Where  it  is  neces- 
sary to  install  gathering  pumps  inby  they  are  usually  operated  by 
electricity;  seldom  by  air.  The  pumps  at  the  shaft  bottom  are 
operated  by  electricity  at  one  mine,  by  air  at  two,  and  by  steam  at 
the  remainder. 

Fig.  7  shows  a  typical  steam  pump  room  near  the  shaft  bottom. 
The  pumps  shown  are  a  No.  8  Knowles  and  a  No.  10  Cameron.  The 
Knowles  pump  was  installed  for  emergency  use. 

The  character  of  the  water  depends  largely  upon  its  source.  Where 
the  faces  of  rooms  supply  a  large  quantity  the  water  is  almost  always 
acid  on  account  of  the  solution  of  iron  pyrites.  Where  shaft  drain- 
age is  the  principal  source  the  water  is  usually  alkaline  or  neutral. 


MINING     PRACTICE 


21 


VENTILATION 

The  subject  of  ventilation  is  a  vital  one  to  the  district  inasmuch 
as  there  have  been  serious  explosions  of  gas  and  dust  in  many 
mines  resulting  in  much  loss  of  life  and  destruction  of 
property.  The  disastrous  explosion  at  the  Zeigler  mine  in  1905  and 
the  fire  in  1908  will  be  recalled  by  those  familiar  with  Illinois  min- 
ing history.  Frequent  explosions  of  less  magnitude  in  other  mines, 
many  of  them  resulting  in  loss  of  life  and  all  of  them  entailing  great 
expense  in  recovering  the  mine  or  a  portion  of  it,  have  caused  this 
district  to  be  regarded  properly  as  a  dangerous  one.a  The  mines  less 
than  100  feet  deep  seem  to  be  comparatively  free  from  explosive 
gas.     As  the  rock  strata  of  the  shallow  cover  are  broken  and  in  places 


Fig.   8.     Metal-Lath   Stopping   Replaced  After   Failure  by   Concrete   Monolith 


eroded,  the  spaces  left  by  rock  removal  being  idled  with  sand  and 
clay,  much  of  the  gas  in  the  bed  has  escaped.  Where  the  bed  lies 
at  depths  greater  than  100  feet  it  is  usually  undrained  and  contains 
the  greater  part  of  the  gas  originally  formed  in  it.  Mallard  states 
that  gas  impregnates  a  coal  bed  jnsl  as  water  impregnates  ;i  porous 
substance  and  that  its  escape  results  directly  from  a  difference  of 
pressure  between  the  interior  and  the  exterior  of  the  mass.  The 
highest  pressure  of  gas  in  the  solid  coal  which  was  recorded  by  I  Jar- 
ton  in  ibis  district  was  33  pounds  per  square  inch  although  the 
pressure  is  probably  higher  in  certain  areas.  However,  a  difference 
in  pressure  of  a  few  pounds  only  is  sufficient  to  set  up  a  steady  flow 

a  After    this    bulletin    had    gone    to    press,    an    explosion    al    the    North    Mine,    Royalton,    on 
October    27,    1014,    resulted    in    the    loss    of   52   men. 


22 


COAL     MINING     INVESTIGATIONS 


of  gas  from  the  coal  into  the  workings.  The  actual  volume  of  gas 
found  in  the  return  air  current  at  any  time  will  depend  chiefly  upon 
the  number  of  active  working  places  in  the  mine  unless  the  bed 
contains  large  storage  basins  of  gas,  that  is,  it  will  depend  upon  the 
area  of  fresh  coal  face  exposed  daily.  This  statement  is  borne  out 
by  Darton's  findings  in  this  district.  In  one  mine  418  feet  deep  with 
a  daily  production  of  2,300  tons  he  records  181  cubic  feet  of  methane 
per  minute  in  the  return  air  current  when  the  mine  was  operating 
and  78  cubic  feet  per  minute  after  a  suspension  of  5  to  15  days.  In 
the  flat-lying  undisturbed  Illinois  beds,  depth  over  200  feet  does  not 
seem  to  be  a  factor  in  the  amount  of  eras  in  the  bed.1 


Fig.  9.     Leaky  Gob  Stopping 


The  presence  of  large  volumes  of  gas  can  not  be  predicted  for 
any  area  unless  it  is  known  by  previous  workings  that  the  area  is 
one  in  which  the  coal  is  broken  by  structural  movement  so  that  it 
acts  as  a  reservoir  for  a  considerable  surrounding  area  of  the  bed. 
In  the  deeper  mines  of  this  district,  however,  there  is  a  continuous 
emanation  of  gas  from  the  fresh  coal  and  such  reservoirs  may  be 
broken  into  at  any  point.  Although  different  exposures  of  fresh 
coal  do  not  give  off  uniform  quantities  of  gas,  some  exuding  none 
and  some  large  quantities,  the  aggregate  emanation  is  considerable. 
The  return  air  in  the  upcast  shaft  at  one  mine  contained  0.28  per 
cent  methane.  The  irregularity  of  emanation  in  different  sections 
is  well  illustrated  at  one  mine  where  the  upcast  air  contained  0.20 

1.     Darton,    N.    H.,    Occurrence    of    Explosive    Gases    in    Coal    Mines,    U.    S.    Bureau    of 
Mines,   Bulletin  72. 


MINING    PRACTICE 


23 


per  cent  methane  and  a  cross  entry,  on  which  there  were  23  work- 
ing places,  near  its  intersection  with  the  main  entry  contained  1.08 
per  cent.  In  another  mine  with  0.26  per  cent  methane  in  the  main 
return,  samples  taken  in  two  rooms  at  the  face  showed  5.53  per  cent 
in  one  and  10.35  per  cent  in  the  other. 

In  almost  every  mine  examined  gas  is  found  in  development 
entries  and  in  the  face  of  all  workings  driven  to  the  rise.  Inasmuch 
as  naked  lights  are  allowed  throughout  the  district  the  safety  of  the 
miners  depends  upon  the  thoroughness  of  the  examination  of  the 


Fig.    10.     Stopping    Built    of   Old    Tics   and    Fine    Gob    (Photo   by   R.    Y.    Williams) 


mine  examiner.  A  single  dereliction  of  duty  may  resull  in  great 
loss  of  life  and  the  wrecking  of  the  mine.  In  many  mines  the  use 
of  naked  lights  should  he  prohibited  unless  the  quantity  of  air  sup- 
plied to  the  face  is  very  materially  increased.  In  n  few  mines  the 
use  of  safety  lamps  in  certain  sections  is  insisted  upon,  l>n(  mixed 
lights  are  often  dangerous  and  in  oilier  states  have  frequently  caused 
serious  explosions. 

Wherever  workings  in  a  gassy  mine  have  been  abandoned  they 
are  usually  sealed  off  by  stoppings  of  various  materials.  A  large 
ainoiin!  of  methane  soon  collects  in  these  abandoned  areas.  Iii  one 
mine   in   which  a  squeezed  area  has  been  sealed  off  by  a  concrete 


24 


COAL     MINING    INVESTIGATIONS 


stopping,  air  samples  drawn  through  a  3-inch  relief  pipe  in  the 
stopping  showed  38.17  per  cent  methane.  It  is  reported  that  since 
the  data  on  which  this  bulletin  is  based  were  collected  all  sealed-off 
areas  in  Franklin  County  have  been  opened  up  and  ventilated.    They 


Fig.   11.     Mud-Plastered  Gob  Stopping  Covered  With  Wood  Fibre   (Photo  by  R.  Y.  Williams) 

are  a  source  of  danger,  and  the  employment  of  more  face  bosses  to 
insure  a  more  frequent  examination  of  the  working  places  and  a 
more  careful  observation  of  all  districts  near  sealed-off  areas  would 
be  conducive  to  greater  safety.  The  accidental  destruction  of  a 
seal  if  unnoticed  for  a  few  hours  would  probably  result  in  a  danger- 
ous explosion. 


MINING     PRACTICE 


25 


In  a  few  gassy  mines  ventilation  inby  is  not  efficient.  In  the 
older  mines  stoppings  are  poorly  constructed  and  leaky.  In  one 
mine  with  wood  stoppings  a  careful  study  by  J.  T.  Ryan,  U.  S. 
Bureau  of  Mines,  showed  only  12^  per  cent  ventilating  efficiency. 
Frequently  only  20  per  cent  of  the  air  supplied  by  the  fan  reaches 
the  last  crosscuts  in  the  cross  entries.  The  remaining  80  per  cent 
short-circuits  through  the  stoppings  into  the  return.  Even  in  some 
of  the  newer  mines  a  false  economy  in  building  permanent  stoppings 
is  proving  expensive.  Concrete  stoppings  are  built  at  few  mines. 
Fig.  8  shows  the  results  of  attempting  to  decrease  initial  cost  of 
stopping  building.  In  the  foreground  is  the  remaining  portion  of 
a  stopping  built  of  f-inch  mesh  expanded  metal  nailed  on  props. 


Fig.   12.     Board   Stopping  Having  Cracks    Plastered   With    Wood-Fibre. 

One  side  of  the  expanded  metal  was  plastered  with  w I  -fibre  |-inch 

thick.  The  metal  rusted  and  the  stoppings  fell  in  six  months.  They 
were  replaced  by  concrete  monoliths,  as  shown,  with  1  part  Portland 
cement  and  0  parts  sifted  cinders.  Fig.  9  shows  a  leaky  gob  stop- 
ping. The  loose  gob  is  tamped  and  held  in  place  between  two  walls, 
each  2  feet  thick,  built  of  shale.  Fig.  10  shows  a  stopping  with 
low  efficiency.  It  is  built  of  old  ties  and  gob  with  fine  gob  thrown 
into  the  spaces  between  the  ends  of  the  ties. 

A  gob  stopping  with  its  face  mud  plastered  and  covered  with 
wood-tibre  (See  fig.  11)  gave  8  per  cent  efficiency  as  determined  by 
anemometers. 

A  favorite  stopping  is  shown  in  fig.  12.      It  is  constructed  <,j' 


kG 


COAL     MINING    INVESTIGATIONS 


1-inch  boards,  6  inches  wide,  nailed  to  props.     The  cracks  between 
boards  are  filled  with  wood-fibre.     This  stopping  is  cheap  to  construct 


rv  \  v* 


Fig.   13.      Efficient   Brick   Stopping 


and  when  first  built  is  efficient,  but  it  soon  becomes  leaky  and  the 
repair  expense  is  large. 

Berkytt  lath  nailed  to  props  and  covered  with  wood-fibre  ^-inch 


Fig.    14.     Retaining   Wall   of   Concrete  Having  Aggregate  of   Sand  and   Slack  Coal 

thick  makes  a  stopping  which  is  efficient  for  a  short  time.  Two  men 
can  build  three  of  these  stoppings  a  day.  One  100-pound  sack  of 
wood-fibre  costing  $10  per  ton  f.  o.  b.  mine  will  cover  one  8  by  10 


MIXING    PRACTICE  Xi 

stopping.  Berkytt  lath  bought  in  lengths  to  fit  a  mine  car  costs 
$15.50  per  thousand  hoard  feet. 

In  a  few  mines  efficient  brick  stoppings  have  been  built,  as 
shown  in  fig.  13.  This  stopping  has  one  course  of  brick  laid  on 
the  broad  side.     The  rib,  roof,  and  floor  are  cut  away  for  a  depth  of 

6  inches  to  provide  a  tight  joint.  In  the  center  a  stiff ener  course  is 
laid  at  a  right  angle  to  the  other  bricks.  Mortar  is  made  of  1  part 
Portland  cement  and  3  parts  sand.  After  the  bricks  are  laid,  both 
sides  of  the  stopping  are  plastered  -J-inch  thick  with  this  mortar.     A 

7  by  12  stopping  is  said  to  cost  $12. 

In  one  mine  stoppings  are  made  of  concrete  with  unusual  in- 
gredients.   One  part   Portland  cement  is  mixed  with   2   parts   sand 


and  5  parts  slack  shoveled  from  the  Hour.  The  larger  pieces  of  coal 
in  the  slack  are  picked  out  by  hand.  The  retaining  wall  shown  in 
fig.  14  is  built  of  this  concrete  which  is  an  excellent  one  for  the 
purpose.  Stoppings  with  this  mixture  in  good  condition  were  noted 
which  had  been  in  place  1  1  years. 

In  another  mine  there  are  a  Jew  stoppings  built  of  concrete 
blocks  although  in  it  there  are  many  leaky  stoppings  of  wood.  These 
blocks,  6  by  10  by  20  inches,  are  made  on  the  surface  with  the  pro- 
portions: 1  Portland  cement ;  2  sand ;  7  sifted  cinders.  It  is  doubtful 
if  this  mixture  is  rich  enough  to  obtain  the  desired  permanency  of 
block.     They  are  said  to  cost  4  cents  each  at  the  pit  month. 

Overcasts  are  built  of  wood,  wood  covered  with  cement,  brick, 
and   concrete.      An  overcast  with   wood   framework  covered    with    1 .', 


28 


COAL     MINING     INVESTIGATIONS 


inches  of  Portland  cement  is  built  at  one  mine  for  $40.  When  first 
constructed  this  overcast  is  tight  but  its  repair  expense,  which  could 
not  be  determined,  is  probably  heavy.  Fig.  15  shows  a  permanent, 
air-tight  overcast  which  has  no  repair  expense.  It  is  built  of  con- 
crete with  the  proportions :  1  Portland  cement ;  2  river  sand ;  2  un- 
sifted cinders. 

The  coal  dust  of  the  district,  judging  from  laboratory  tests  only 
(See  Table  7)  gives  lower  pressure  in  the  initiation  of  an  explosion 
than  the  dust  of  some  other  districts,  but  judging  from  past  explo- 
sions this  dust  when  an  explosion  is  once  initiated  in  a  mine  will 
propagate  as  violently  as  any  other. 

Table  7. — Pressure  developed  by  dust  of  face  samples  in  explos- 

ibility  apparatus 


District 

No. 
samples 

Pressure  in 
pounds  per 
square  inch 

at  2192 
degrees  F. 

I 

11 
5 
5 

17 
7 

16 

24 
6 

8  400 

II 

5.880 

Ill 

IV 

7.805 
7  700 

V 

7.105 

VI 

5  950 

VII 

7  175 

VIII 

8  925 

At  a  few  mines,  notably  those  in  which  there  have  been  explo- 
sions, attempts  are  made  to  lessen  the  danger  of  a  coal  dust  explosion. 
At  one  mine  water  is  pij^ed  to  the  face  of  every  room  and  the  ribs, 
roof,  and  props  of  every  room  are  hosed  before  shooting.  In  a  few 
other  mines  the  ribs  of  entries  are  hosed  every  two  weeks.  In 
another  mine  the  haulage  roads  are  ballasted  with  ashes.  It  takes 
76  cubic  feet  of  ashes  to  cover  40  linear  feet  of  road.  When  the 
road  bed  becomes  covered  with  coal  dust  more  ashes  are  sprinkled 
on  it.  The  roads  are  sprinkled  with  water  nightly.  In  this  mine 
an  explosion  which  killed  8  men  died  out  for  lack  of  explosive  dust 
after  traversing  a  short  stretch  of  entry  in  which  ash  ballast  had 
been  used. 

Inasmuch  as  in  many  mines  the  floor  of  entries  is  covered  with 
several  inches  of  dust  and  slack,  regular  sprinkling  with  water  cars 
is  usually  done.  At  one  mine  the  cost  of  sprinkling  is  -J  cent  per 
ton  of  coal  hoisted.     The  total  ventilating  cost  of  this  mine,  excluding 


MINING    PRACTICE 


29 


steam  used  by  the  fan  engine,  but  including  trappers,  mine  examiners, 
brattice  cloth,  and  labor  on  brattices  is  i-cent  per  ton  of  coal  output. 
Humidification  of  the  air  is  attempted  at  only  three  of  the 
examined  mines.  In  all  three  cases  exhaust  steam  from  the  fan 
engine  is  turned  into  the  intake  air-shaft  in  winter  to  prevent  the 
formation  of  ice  in  the  shaft.  At  one  of  these  mines  the  exhaust 
steam  is  carried  over  a  radiator  heated  by  live  steam.  The  radiator 
is  made  of  1,000  feet  of  1^-inch  pipe.  One  of  the  mines  using  ex- 
haust steam  reports  that  it  causes  the  roof  to  fall  badly.     In  winter 


Steel    Hay    C 


Photo    by    K.    Y.    Williams) 


20  readings  with  a  sling  psychrometer  at  the  faces  of  rooms  gave  an 
average  relative  humidity  of  00  per  cent  and  an  average  temperature 
of  G4-J-  degrees  F.  A  hygrometer  installed  in  the  return  near  the 
upcast  shaft  of  a  typical  mine  G40  feet  deep,  producing  2,400  tons 
daily,  was  read  three  times  daily  for  a  year.  These  readings  show 
that  the  average  temperature  of  the  return  air  Avas  r>r>.  1  degrees  F. 
and  the  relative  humidity  97.7  per  cent.  A  detailed  report  on  the 
humidity  of  air  in  Illinois  mines  is  given  in  Bulletin  83,  U.  S. 
Bureau  of  Mines,  The  Humidity  of  Mine  Air,  by  R  Y.  Williams. 
There  have  been  numerous  small  fires,  started  in  nearly  every 


30 


COAL     MINING    INVESTIGATIONS 


MINING    PRACTICE 


31 


case  by  the  ignition  of  the  coal  after  shooting  with  black  powder. 
Such  a  fire  in  one  mine  affected  1,300  feet  of  both  of  a  pair  of  cross 
entries,  and  was  sealed  off  by  a  wall  of  cement-and-cinder-concrete  2 
feet  thick.  Several  small  fires  have  been  shut  off  with  board  seals, 
and  many  of  them  have  been  quenched  with  water. 

In  many  mines  lubricating  oil  is  stored  in  barrels  in  the  run 
around,  but  in  some  it  is  taken  below  in  3-gallon  cans  as  needed. 

The  transportation  of  hay  to  stables  where  mules  are  kept  under- 
ground is  attended  with  more  care  than  in  any  other  district  in 
Illinois.     In  almost  every  mine  examined  the  provisions  of  the  State 


Fig.    17. 


•pical    Underground    Stable 


law  with  regard  to  the  transportation  of  hay  to  underground  stables 
are  scrupulously  observed.  The  hay,  which  is  baled,  is  carried  in  a 
specially  constructed  car.  Fig.  L6  shows  a  steel  hay  car  in  an  under- 
ground stable  in  which  a  concrete  walled  room  is  provided  lor  the 
storage  of  small  quantities  of  hay.  This  stable  cost  about  $(1,000  to 
build. 

The  type  of  underground  stable  found  in  most  mines  in  the 
district  is  shown  in  fig.  IT.  At  several  mines  the  mules  are  stabled 
on  the  surface.  At  one  mine  having  24  mules  on  the  secondary 
haulage  they  are  hoisted  out  each  night.  It  requires  thirty  minutes 
to  hoist  and  the  same  time  to  lower  them.  The  total  expense  of  these 
operations  is  $0.000888  per  ton  of  coal  hoisted. 

Oil  lamps  are  in  more  general  use  by  the  miners  than  in  any 


32  COAL     MINING     INVESTIGATIONS 

other  district.  At  one  mine  the  management  forbids  the  use  of 
carbide  lamps.  The  smoky  oil  lamps  pollute  the  air  in  rooms.  In 
mines  where  they  are  used,  air  at  the  working  face  is  noticeably 
more  impure  than  where  carbide  is  burned. 

Table  8  gives  ventilating  equipment  for  the  mines  examined. 

BLASTING 

In  District  VI  over  half  the  coal  mined  is  undercut  by  machines. 
During  the  year  ended  June  30,  1912,  there  were  6,379,704  tons 
undercut,  53.3  per  cent  of  the  total  tonnage.  At  three  of  the  mines 
examined  puncher  machines  operated  by  compressed  air  are  used ; 
at  one  both  electric  chain  machines  and  puncher  machines ;  at  eight 
electric  chain  machines ;  and  at  three  the  coal  is  shot  off  the  solid. 
With  chain  machines  the  usual  practice  is  to  fill  two-thirds  of  the 
chain  with  chisel  bits  and  one-third  with  pick  bits.  At  some  mines, 
however,  pick  bits  can  not  be  used  because  the  coal  below  the  blue 
band  is  too  hard.  Puncher  machines  give  an  average  daily  output 
each  of  50  to  70  tons  and  chain  machines  a  tonnage  of  100  to  165. 
Table  9  gives  data  on  blasting  practice. 

Although  99.5  per  cent  of  all  the  permissible  explosives  used  in 
Illinois  are  used  in  this  district  the  amount  of  permissibles  used  was 
only  326,925  pounds  during  the  year  ended  June  30,  1912,  as  com- 
pared with  5,909,175  pounds  of  black  powder.  In  Franklin  County 
the  amount  of  permissibles  used  is  increasing  each  year  and  at 
present  they  are  used  at  all  but  a  few  mines.  In  no  other  district 
in  Illinois  is  the  necessity  for  the  use  of  permissibles  so  apparent 
as  in  this.  With  explosive  gas  in  quantities  large  for  Illinois  and 
with  an  explosible  dust  the  use  of  a  long-flame  explosive  should  be 
prohibited.  Nearly  every  mine  in  the  district  has  had  one  or  more 
fires  and  explosions  caused  by  the  flame  of  black  powder  igniting 
feeders  of  gas  near  the  face.  As  tested  in  an  unyielding  steel  cannon 
the  flame  of  black  powder  will  extend  more  than  three  times  as  far 
into  the  open  air  as  the  flame  of  an  equivalent  shot  of  permissible 
explosive,  and  in  coal,  owing  to  the  quick  action  of  the  permissible, 
the  drill  hole  will  be  enlarged  and  in  many  cases  the  flame  will  not 
emerge  from  the  hole.  In  order  to  ignite  inflammable  gas  and  dust 
mixtures  a  high  temperature  acting  through  a  certain  length  of  time 
is  necessary.  The  flame  temperatures  of  all  explosives  are  higher 
than  is  necessary  to  ignite  these  inflammable  mixtures,  and  the 
duration  of  black  powder  flame  is  much  longer  than  the  minimum  for 
an  ignition.  The  flame  of  permissible  explosives  in  proper  charges 
properly  detonated  is  of  such  short  duration  that  it  does  not  ignite 


MINING     PRACTICE 


33 


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34 


COAL     MINING    INVESTIGATIONS 


these  mixtures.     The  quantity  of  permissible  used  for  a  shot  should 
not  exceed  1^  pounds. 

Permissible  explosives,  referring  to  the  characteristic  component 
of  each,  may  be  divided  into  four  classes:  Ammonium  nitrate; 
hydrated;  organic  nitrate  (other  than  nitroglycerin);  nitroglycerin. 
In  Illinois  only  the  nitroglycerin  powders  are  used.  They  contain 
free  water  or  an  excess  of  carbon  for  the  reduction  of  flame  tempera- 
ture and  usually  contain  salts  that  decrease  their  strength  and  shat- 
tering effect.  They  detonate  easily  and  are  very  little  affected  by 
moisture.  The  explosive  is  usually  purchased  in  cartridges  7  to  8 
inches  long  and  If  inches  in  diameter.     In  one  mine  a  test  showed 


Fig.    18.     Method    of    Placing    Holes    When    Black    Powder    Is    Used 

that  25  pounds  of  a  permissible  gained  180  tons  of  coal  and  25 
pounds  of  black  powder  91  tons.  Permissible  explosives  are,  there- 
fore, cheaper  for  the  miner,  as  25  pounds  of  black  powder  cost  $1.75 
and  25  pounds  of  a  permissible  explosive  $2.45.  It  is  generally 
supposed  that  a  permissible  explosive  with  its  greater  shattering 
effect  gives  a  larger  per  cent  of  slack  coal.  This  depends  in  a  great 
measure  upon  the  manner  in  which  it  is  used  and  the  physical 
characteristics  of  the  coal.  Used  properly  it  is  doubtful  if  a  per- 
missible makes  more  slack.  At  one  mine  with  black  powder  65  per 
cent  of  the  coal  gained  was  lump  over  1^  inches,  and  with  a  per- 
missible, 55  per  cent.  Ten  of  the  mines  examined  used  black  powder; 
one  used  permissibles  in  some  sections  and  black  powder  in  others; 
and  four  used  only  permissibles. 

Fig.   18  shows  a  typical  method  of  placing  holes  where  black 


MINING     PRACTICE 


35 


powder  is  used ;  the  arrangement  of  holes  charged  with  a  permissible 
is  shown  in  fig.  19.  In  the  mines  of  this  district  charges  of  per- 
missibles  are  fired  with  fuse  and  caps ;  black  powder  is  fired  with 
sqnibs  in  eight  mines  and  with  fuse  in  two.  Missed  holes  are  fre- 
quent at  mines  using  black  powder.  From  statements  of  shot-firers 
in  this  district,  it  is  estimated  than  an  average  of  2  per  cent  of  all 
shots  misfire.  Greater  safety  and  a  decrease  in  the  number  of  mis- 
fires could  be  ensured  by  the  use  of  electric  detonators. 

The  frequency  of  fires  after  shots  makes  fire-runners  necessary 
particularly  in  mines  using  black  powder. 

At  two  mines  the  miners  are  allowed  to  fire  their  own  shots. 
Black  powder  is  used  at  both  these  mines.     It  is  not  safe  to  allow 


Fig.   19.     Method   of  Placing  Holes  When   Permissible   Explosives   Are   Used 

miners  to  do  their  own  shooting  in  a  gaseous  district,  because  it  is 
difficult  to  prevent  them  from  using  coal  cuttings  for  tamping  and 
from  overcharging  the  holes.  Several  holes  thai  came  under  observa- 
tion in  the  district  were  tamped  with  cuttings.  Where  shot-firers  are 
employed  the  number  of  holes  fired  per  man  varies  from  45  to  250. 

At  one  mine  al]  holes  are  drilled  with  air-drills.  Unless  the 
miner  desires  to  point  his  own  holes,  which  is  seldom,  all  holes  are 
pointed  by  the  drill-runner.  The  operator  of  this  mine  states  that 
on  account  of  the  differential  in  wage  scale  he  finds  no  advantage  in 
the  use  of  power  drills. 

At  one  mine  in  this  districl  a  hydraulic  mining  machine  has 
been  tested.  The  machine  did  not  perform  successfully  on  account 
of  the  strength  of  the  coal  and  the  lack  of  cleat. 

In  that  mine  in  which  entries  are  driven  on  two  benches,  shoot- 


36 


COAL     MINING    INVESTIGATIONS 


ing  is  done  with  size  F  black  powder,  and  the  holes  are  arranged  as 
shown  in  fig.  20.  The  hand-shearing  is  carried  down  to  the  first 
bench  and  driven  ahead  8  feet.  The  reliever  (block)  shot  is  fired 
first,  the  two  rib  shots  next,  and  the  sump  shot  in  the  lower  bench,  last. 
More  powder  in  paper  kegs  is  used  in  this  district  than  in  any 
other.  The  paper  keg  does  not  make  a  spark  when  opened  with  a 
pick  point.  In  spite  of  the  provision  of  the  State  law  making  it  a 
criminal  offense  for  a  miner  to  have  in  his  possession  a  steel  powder 


Fig.   20.     Method  of  Shooting  With  Two   Benches 


keg  which  has  in  it  a  hole  made  by  a  pick  point,  this  method  of 
opening  kegs  is  often  employed. 

For  the  transportation  of  powder  from  the  top  to  the  partings, 
special  cars  have  been  built  at  several  mines.  Several  explosions 
of  powder  during  transport  in  the  last  two  years  in  the  district 
resulting  in  loss  of  life  and  partial  wrecking  of  the  mines  emphasize 
the  need  of  specially  protected  cars  for  the  delivery  of  powder  to 
the  face.a 

To  insure  the  safety  of  the  miner  in  this  district  shooting  off 

a  After  this  bulletin  had  gone  to  press,  48  kegs  of  powder  exploded  during  transpor- 
tation in  an  open  car  in  the  Majestic  mine,  Duquoin,  on  October  1,  1914,  killing  one  man 
and  wrecking  the  mine. 


MINING     PRACTICE 


37 


the  solid  should  be  prohibited,  the  use  of  black  powder  forbidden, 
and  the  number  of  face-bosses  increased  to  prevent  tamping  with 
coal  cuttings.  Expert  and  careful  shot-firers  should  be  employed 
and  the  feasibility  should  be  investigated  of  firing  all  shots  from 
the  surface  with  electric  detonators  and  batteries  when  all  the  men 
are  out  of  the  mine  as  is  done  in  some  mines  in  Utah,  Colorado,  and 
Alabama. 

TIMBEKING 

The  gray  shale  above  the  coal  does  not  stand  well  when  exposed 
to  the  air  and  to  protect  it  the  top  coal  above  the  charcoal  parting 
in  rooms  and  entries  is  left  wherever  possible.     This  top  coal  makes 


Fig.    21.     Solid   Concrete    Pier   at    lira 


a  good  roof  where  it  is  not  broken  by  overcharged  shots.  In  several 
mines  there  is  no  timbering  in  the  entries.  Where  the  top  coal  is 
broken  or  removed  heavy  timbering  is  often  necessary.  The  3-piece 
entry  set  in  one  mine  is  made  up  with  a  white-oak  collar  12  by  12 
inches  on  8  by  12  legs.  In  this  mine  at  branches  or  partings  the 
point  of  the  coal  pillar  is  cut  away  for  about  10  feet  and  the  roof 
supported  by  a  brick  pier  tilled  with  gob.  The  total  timber  cost  at 
this  mine  is  5  cents  per  ton  of  coal  hoisted.  The  average  cost  of 
timber  at  the  mines  examined  is  2-J  cents  per  ton  of  coal.  The 
lowest  cost  is  J-cent  per  ton.  At  one  mine  the  point  of  the  coal  pillar 
at  cross  entries  is  cut  back  20  feet  and  the  root*  supported  by  a  solid 
concrete  pier,  as  shown   in  fig.   21.     The  chief  object    in    removing 


38 


COAL     MINING     INVESTIGATIONS 


Fig.    22.     Cog  Timbering  at   Parting 


Fig.    23.     Shaft    Bottom    With    Roof    Supported    by    Steel    I-Beams    Set    on    Concrete    Walls 
(Photo  by   R.   Y.   Williams) 


MINING    PRACTICE 


39 


the  coal  at  pillar  points  and  building  brick  or  concrete  piers  is  to 
provide  a  substantial  roof  support  which  will  not  be  knocked  away 


Fig.    24.     Typical   Room    Propping 

if  hit  by  a  trip  which  happens  to  leave  the  track  when  rounding  the 
curve. 

At  one  mine  where  wide  partings  are  built  the  roof  is  supported 


Mouth    of    Concrete    Lined    Shah 


by  cogs  8   feet  square  built  of  6-inch   props,  as  shown    in    fig. 
These  cogs  are  not  filled  with  gob  and  are  weaker  than   filled 
used  in  longwall  mining  in  Illinois. 


9.9, 


40 


COAL     MINING     INVESTIGATIONS 


In  several  mines  steel  I-beams  are  used  for  roof  support,  espe- 
cially at  the  shaft  bottoms.  At  one  mine  the  roof  of  the  shaft  bottom 
is  supported  by  18-inch  75-pound  I-beams  set  on  6-foot  centers  with 
short  white  oak  legs  8  inches  square  set  in  hitches  cut  in  the  rib.  In 
the  entries  steel  rails  weighing  50  pounds  per  yard  are  set  on  6-foot 
centers  for  10-foot  spans.  For  spans  greater  than  10  feet  66-pound 
rails  are  used  on  6-foot  centers. 

The  use  of  steel  I-beams  as  roof  supports  seems  to  be  econom- 
ical in  this  district.  A  12-inch,  4-0-pound  I-beam  12  feet  long  costs 
about  $3.75  in  place.  Timber  crossbars  break  frequently  at  nearly 
every  mine  in  the  district ;  one  instance  was  noted  where  timber 
collars  were  replaced  four  times  in  18  months. 

Table  10. — Data  concerning  props  in  rooms 


Mine  No. 


50. 

51. 

52. 

53. 

54. 

55. 

56. 

57a 

58., 

59. 

60. 

62. 

63. 

64.. 

65.. 


2.3 
2.2 
4.0 
0.9 
5.5 
2.7 
4.7 

2^8 
4.0 
2.2 
2.0 
3.0 
2.5 
2.4 


t/5 

CD 

G     ^ 

CD 

CD     CT^ 

<+H 

t  in  c 
100  s 

f  roo 

CD    ^ 

w  .    c 

c3-S 

CD    bfl 

CD    g 

O    nj      • 

>  C 

ti  ° 

U  a£ 

Q.5 

<^ 

3  e 

32.2 

4^ 

7 

12 

17.3 

5 

8 

18 

29.0 

4 

7U 

24 

7.9 

5 

m 

60 

41.3 

4 

7V?, 

24 

24.3 

m 

8 

36 

34.1 

5 

7M 

24 

2L0 

4  " 

7V?' 

18 

34  0 

5 

m 

24 

29.7 

4 

8 

18 

16.0 

4^ 

7V?, 

24 

21.0 

5H 

7 

36 

21.9 

5 

7V?, 

24 

21.0 

5 

7Y2 

18 

°  Z 

&  o 


Both 

Both 

Both 

Both 

Both 

Round 

Both 

Split  ' 

Both 

Both 

Both 

Beth 

Both 

Both 


aNo  props  used  in  rooms. 

Fig.  23  shows  a  shaft  bottom  having  its  roof  supported  by  steel 
I-beams  with  ends  resting  on  concrete  walls. 

Because  top  coal  is  left  in  place  in  rooms  the  number  of  props 
per  100  square  feet  of  roof  is  low.  Fig.  24  shows  the  position  of 
props  in  a  typical  room  in  a  mine  where  the  average  number  of  props 
per  100  square  feet  of  roof  is  4.7.  This  number  is  rather  high  for 
the  mines  examined.  The  figures  in  Table  10  for  number  of 
props  per  100  square  feet  of  roof  were  obtained  by  counting  the 
number  of  props  in  several  typical  rooms  whose  width  and  length 
were  measured.  Props  are  of  various  woods,  and  it  is  seldom  that 
over  5  per  cent  are  of  white  oak.     Both  split  and  round  props  are 


MINING    PRACTICE 


41 


usually  bought.  One  mine  buys  split  props  only;  another  uses  only 
the  round.  The  number  of  room  props  purchased  per  ton  of  coal 
hoisted  varies  from  2  to  6. 

It  is  desirable  to  have  more  frequent  inspections  of  the  working 
places.  Rooms  were  examined  in  which  the  nearest  prop  to  the  face 
was  30  feet  from  it.  As  heavy  shooting  often  breaks  the  top  coal, 
no  miner  should  be  allowed  to  leave  such  a  length  of  unsupported 
roof. 

The  hoisting-and-air  shafts  at  each  mine  examined  are  timber- 
lined,  having  been  sunk  before  the  provision  requiring  fireproofed 
shafts  was  introduced  into  the  State  Mining  Law.  Shafts  which  have 
been  sunk  since  this  provision  went  into  effect  are  concreted.  Fig.  25 
shows  the  mouth  of  a  concrete-lined  shaft.  Three  of  the  walls  of 
the  lining  have  been  continued  above  the  surface  landing  as  an  acci- 
dent prevention.     The  fourth  side  is  protected  by  a  heavy  steel  bar- 


gate. 


HAULAGE. 


The  faulting  of  the  ~No.  6  bed  occasions  difficulty  in  obtaining 
the  speediest  and  most  economical  haulage,  but  otherwise  physical 
conditions  are  excellent  and  the  thick  bed  allows  large  cars  to  be 
used.     Where  faults  are  met  the  difference  in  elevation  is  usually 


Fig. 


Underground    Machine   Shop 


overcome  by  a  chain  automatic  car-haul,  but  in  two  mines  the  loads 
from  the  high  side  of  the  fault  are  lowered  by  a  cable  and  drum 
down  an  incline. 


42 


COAL    MINING    INVESTIGATIONS 


Equipment  for  haulage  is  better  in  general  than  in  any  other 
district  in  the  State.  In  several  mines  there  are  tight  steel  cars  of 
large  capacity,  many  of  which  have  roller-bearing  wheels.  The  aver- 
age weight  of  empty  pit  cars  at  the  mines  examined  is  2100  pounds, 
their  capacity,  5588.  The  amount  of  coal  carried  in  the  average  car 
is,  therefore,  2.7  times  the  weight  of  the  car.  The  weight  of  the 
average  car  is  27.1  per  cent  of  the  total  weight  of  car  and  coal. 
Track  gages  are  wider  and  rails  are  heavier  than  in  mines  in  Dis- 
trict VII  working  in  bed  6  west  of  the  Duquoin  anticline.     In  11 


Table  11. — Ton  mileage  of 

locomotives 

> 

o  o 

£  8 

Weight  of 
locomotive 
in  tons 

Miles  traveled 
per  shift  by 
locomotive 

Ton  mileage  per  shift 

Mine  No. 

w 

u 

o 
i— i 

Id 

o 

C 

15 

50 

Electric 

Electric 

Electric 

Electric 

Electric 

Rope  haulage 

Electric 

Electric 

Electric 

Electric 

Electric 

Electric 

Electric 

Gasoline 

Electric 

15 
10 

12 

i2 
"io" 

8 
13 
15 
13 
10 

"8" 

8 

18.9 

9.5 

30.7 

"q.S 

'22^8* 

"u.'i 

37.9 
27.3 
27.3 

35.0 

341 

96 

518 

"*68" 

"i25* 

"614* 
947 
360 

287 

*185 

210 

455 
200 

748 

"255* 

'"457" 

"767' 

1093 

491 

458 

'  273' 
525 

796 

51 

52 

296 
1266 

53 

54 

320 

55 

56 

592 

57 

58 

59 

1381 
2040 

60 

851 

62 

63 

64 

65 

745 

"458' 
735 

of  the  mines  examined  the  track  gage  is  42  inches.  Kiail  weight  on 
the  main  haulage  varies  from  25  to  60  pounds. 

At  none  of  the  mines  examined  are  mules  used  on  the  main 
haulage.  In  certain  sections  of  five  mines  electric  locomotives  weigh- 
ing either  5  or  6  tons  are  used  in  gathering.  Mules  are  kept  in 
good  condition  and,  because  the  floor  is  comparatively  level  where 
gathering  is  done,  rail-weights  on  the  cross-entries  sufficiently  heavy, 
and  running-gear  of  cars  well  cared  for,  they  should  make  a  high 
ton-mileage  per  shift.  No  figures  were  available,  however,  as  the 
recording  of  the  work  done  by  mules  is  not  deemed  necessary.  The 
cost  of  a  1000-pound  mule  varies  from  $175  to  $250,  depending  upon 
age  and  condition  at  time  of  purchase. 

The  performance  of  electric  locomotives  on  the  main  haulage 
varies  from  296  ton-miles  per  day  to  2040.     Table  11  gives  data  on 


MINING    PRACTICE 


43 


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pOO  JO  OT^B'JJ 


00  CO00       "^  CO       oo 
OO  »-t  O        iO  l>        »OiO 

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i-i  <N  CO  CO<N<M 


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sjbo  jo  A^p-ed-BQ 


80i0 
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ooooo 
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co  ioi>ioio 


spunod  in 
sj^o-^id  jo  ^uSia^ 


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C0_<M_       Tt,"* 

T-Tof     o<feq 


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one  13 

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44  COAL     MINING    INVESTIGATIONS 

locomotive  performance.  The  chief  cause  of  low  ton-mileage  is  that 
partings  are  not  maintained  close  enough  to  the  working  face  to 
enable  gathering  mules  to  fill  them  with  loads  between  trips  of  the 
locomotive.  A  wait  for  sufficient  cars  to  make  up  a  trip  is  thus  made 
necessary. 

To  keep  locomotives  in  good  repair  there  are  well  equipped 
machine  shops  underground  in  a  few  mines  (See  fig.  26)  and  loco- 
motives are  examined  daily  for  defective  parts  and  poor  adjustments. 
They  are  consequently  kept  up  to  the  highest  possible  mechanical 
efficiency. 

Mixed  ties  with  dimensions  4  inches  by  4  inches  by  5^  feet  are 
usually  bought  for  the  haulage  roads.  Mixed  ties  can  be  bought  at 
Mulkeytown  at  10  cents  f.  o.  b.  They  are  elm,  hickory,  water-oak, 
white-oak,  black-oak,  and  sassafras.  The  average  shipment  contains 
about  1  per  cent  of  white-oak  ties,  which  are  the  most  desirable. 
Mixed  ties  cost  the  middleman  7  cents  each,  of  which  amount  4  cents 
is  paid  for  cutting  and  trimming  in  the  woods  and  3  cents  for  haul- 
ing to  the  shipping  point.  When  white-oak  ties  are  specified  the 
purchaser  pays  15  cents  each  f.  o.  b.  shipping  point,  and  the  middle- 
man 12-J  cents.     About  1000  ties  can  be  cut  from  an  acre  of  timber. 

Koadbeds  are  well  ballasted ;  grades  are  kept  low  and  curves  easy. 

Table  12  gives  haulage  data. 

HOISTING. 

This  district  contains  many  mines  of  comparatively  large  pro- 
duction and  their  hoisting  equipment  is  adequate  to  their  needs,  as  is 
shown  in  Table  13.  The  longest  hoist  at  any  mine  examined  is  726 
feet.  The  operators  have  been  slow  in  installing  automatic  caging 
at  the  bottom ;  better  hoisting  records  could  be  made  at  less  cost  with 
this  improvement.  The  mines  opened  within  the  last  few  years  have 
made  provision  for  caging  automatically.      (Fig.  27.) 

The  shaft  bottoms,  as  in  nearly  all  mines  in  Illinois,  are  too 
short  to  provide  storage  space  for  loads  and  empties  sufficient  to  con- 
tinue hoisting  long  after  an  accidental  interruption  of  haulage. 

The  best  hoisting  record  for  the  district  was  made  by  the  Old 
Ben  Mining  Corporation  at  its  ~No.  8  mine  at  West  Frankfort  on 
June  26,  1914,  when  it  hoisted  4428  tons  in  eight  hours. 

The  shafts  of  all  the  mines  are  of  moderate  size,  the  largest 
being  10  by  20  feet.  Not  much  trouble  was  experienced  in  sinking 
except  at  one  mine  where  a  considerable  body  of  quicksand  necessi- 
tated a  reduction  in  shaft  size. 


MINING    PRACTICE 


45 


Table  13. — Hoisting  data 


to 

.S    " 

'a 

£ 

Hoisting  shaft 

o  c 

Engine 

Drum 

•in  o 

u 

'Sew 

'-^     CD  ^ 

P-S..9 

S.s 

No. 

+*  "in 

Q.S 

CD 

03  .S 

50 

51 

52 

53 

54 

55 

56 

57 

58 

59 

60 

62 

63 

64 

65 

2000 
1200 
2400 
2500 

1600 
1200 
1400 
1600 
2500 
3000 
2250 
2325 
2600 
1350 
1600 

Yes 

Yes 

Yes 

7-ton 

skip 

Yes 

No 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

726 
494 
640 
450 

380 
160 
580 
320 
516 
220 
112 
190 
140 
120 
90 

10      by  18 
9^  by  12 

93i  by  17^ 

7  by  18 

8  by  16 

7  by  16 
1Y2  by  10 

9  by  15 
93^  by  17 

8  by  12 
10      by  20 

9  by  173^ 
10      by  16 
10^  by  14M 

No 

No 

No 

Skip 

No 
No 
No 
No 
No 
No 
No 
No 

'  No  ' 

No 

Yes 
Yes 
Yes 

No 

Yes 
Yes 
Yes 
Yes 
Yes 

'  Yes  ' 
Yes 
Yes 
Yes 
Yes 

28  by  48 
24  by  36 
26  bv  48 
18  by  30 

20  by  36 
16  by  36 
26  by  48 
24  by  36 
24  by  42 
24  by  42 
20  by  36 
24  by  36 
24  by  36 
16  by  32 
24  by  36 

10 

6 

10 

10 

8 

VA 
10 

7 
8 
10 
7V2 
7 
6 

5 

5 
5 

±% 
10 

3 
5 
10 
4 
5 

2 
5 
6 
4 

a  Largest  diameter  when  conical. 
b  2  drums. 


At  every  mine  except  one  the  standard  self-dumping  cage  is 
used.     Here  the  shaft  was  sunk  33  feet  below  the  bottom  of  the  coal. 


mil  i  J* 


Automatic  Caging   Device 


A  bin  was  then  built  with  its  sloping  bottom  extending  from  beyond 
the  tracks  to  the  shaft.  The  pit  cars,  which  are  bottom-dumping, 
unload  when  a  dog  on  the  bottom  of  a  car  strikes  a  cam  between 


46 


COAL    MINING    INVESTIGATIONS 


the  rails.  The  coal  from  this  bin  discharges  into  a  skip  11  feet  deep 
holding  7  tons.  The  shaft  has  three  compartments;  two  6 J  by  7 
feet  each  for  coal  hoisting,  and  one  4  by  7  feet,  for  hoisting  men  by 
cage.  Weighing  is  done  at  the  shaft  bottom  of  this  mine.  On 
account  of  the  great  weight  of  skip  and  load  the  hoisting  engine  is 
second  motion.  At  the  other  mines  first  motion  hoists  are  used,  the 
largest  engine  having  28  by  48-inch  cylinders.  Conical  and  cylin- 
drical drums  are  about  equally  divided  and  their  diameters  range 
from  4^  to  8  feet  for  depths  less  than  500  feet.  For  greater  depths 
they  have  a  diameter  of  10  feet. 

PKEPARATION"  OF  COAL. 

As  regards  the  preparation  of  their  output  for  market  the  mines 
of  this  district  may  be  divided  into  those  which  size  the  raw  coal  on 
shaking-screens  only,  making  four  sizes;  those  which  rescreen  in 
revolving  screens  the  product  passing  through  the  3  or  3^-inch  holes 
of  the  shaking  screens,  making  5  to  7  sizes ;  and  those  which  wash 
the  coal  under  3  or  3^  inches,  making  7  to  9  sizes. 

At  those  mines  where  only  four  sizes  are  sold  the  following 
products  usually  are  made: 


Name 


Size  in  inches 


Per  cent  of 
total  output 


Lump.  .  .  . 
Egg 

Nut 

Screenings 


Over  G 

Over  3;  through  6 
Over  2 ;  through  3 
Through  2 


20 
20 
20 
40 


Where  the  coal  is  rescreened  but  not  washed  and  all  seven  sizes 
are  made,  a  typical  separation  is : 


Name 


Size  in  inches 


Per  cent  of 
total  output 


Lump .  .  .  . 

Egg 

No.  1  nut 
No.  2  nut 
No.  3  nut 
No.  4  nut 
No.  5  nut 


Over  6 
Over  V/2 
Over  1% 
Over  1 
Over  % 
Over  % 
Through 


through  6 
through  2»Y2 
through  \% 
through  1 
through    % 


12 
19 

16.5 
15 

7.5 

7 
23 


F.  C.  Lincoln  in  Bulletin  !No.   69,  Coal  Washing  in  Illinois, 
Engineering  Experiment  Station,  University  of  Illinois,  says  that  no 


PREPARATION    OF    COAL 


4? 


two  washeries  in  Illinois  make  washed  coals  of  exactly  the  same  sizes. 
The  range  in  inches  is  as  follows: 


No.  1 
extra 


No.  1 


No.  2 
extra 


No.  2 


No.  3 


No.  4 


No.  5 


Always  under. 
Always  over.  , 


m 

VA 


1% 


2M 

7% 


m 


316 


V, 


A  special  bulletin  on  the  dry  screening  of  coal  in  Illinois  is  in 
preparation  by  the  Engineering  Experiment  Station,  University  of 
Illinois. 


Tippli 


Nearly  every  mine  ships  some  run-of-mine  coal,  its  per  cent  of 
total  output  varying  at  the  examined  mines  from  5  to  36.  At  no 
mine  is  the  entire  production  shipped  as  run-of-mine. 

At  one  typical  mine  95.7  per  cent  of  the  total  output  is  loaded 
in  railroad  cars,  1.8  per  cent  loaded  in  wagons  at  tipple,  2.2  burned 
under  boilers  of  surface  plants  and  0.3  wasted. 

Table  14  gives  data  on  tipple  equipment  for  coal  preparation. 
At  very  few  mines  in  this  district  is  1  J-ineh  lump  made.    The  figures 


48 


COAL    MINING    INVESTIGATIONS 


for  this  size  which  are  necessary  for  a  comparison  of  percentage  with 
the  rest  of  the  State  were  estimated  by  the  operators. 

Table  14. — Preparation  of  coal  for  market 


No. 


Material 

Shaker  screen 

c   u 

CD 

of  tipple 

<L»    C 

c/2  a 

§1 

Inclina 

inches 

foot 

Is  coal 
rescreened 
or  washed 


Per  cent  of 
total  output 


<D^ 
>    y 

O.S 


,_,    CD 
>    % 

O.S 


51 
52 
53 

r>4 
55 
56 
57 
58 
59 
60 
62 
63 
64 
65 


Steel 

30 

8 

4 

90 

Frame 

24 

8 

5 

70 

Steel 

40 

8 

4 

90 

Steel 

nv? 

8/, 

5 

85 

Frame 

12 

7 

2V2 

40 

Frame 

24 

7 

4 

90 

Steel 

38 

8 

3 

90 

Frame 

46 

6 

3 

90 

Steel 

40 

9 

2 

80 

Frame 

40 

8 

60 

Steel 
Frame 

3 

65 

80 

40 

8 

Steel 
Frame 

16 

10^ 

4 

75 

Frame 

45 

7 

3 

90 

Neither 

Neither 

Rescreened 

Rescreened 

Rescreened 

Both 

Rescreened 

Neither 

Rescreened 

Neither 

Neither 

Both 

Both 

Both 

Neither 


65 
62 
60 
63 
60 
60 
46 
65 
58 
60 
60 
60 


45 

47 


20 
22 
19 
12 

25 
22 

28 
25 
26 
15 
25 


20 

16 


In  general  the  tipples  in  this  district  are  modern  and  efficient. 
Steel  tipples  have  been  built  at  seven  of  the  mines  examined.  (See 
fig.  28.)  Where  they  are  of  frame  construction  as  shown  in  fig.  29 
the  fire  risk  is  minimized  as  much  as  possible. 


Fig.    29.     Frame   Surface   Plant 

The  surface  plant  equipment  at  most  mines  is  adequate  to  handle 
the  tonnage  produced,  as  shown  in  Table  15.  At  a  few  mines,  how- 
ever, the  boiler  installation  is  too  small  to  maintain  continuous  hoist- 
ing throughout  the  working  day  and  hoisting  is  often  interrupted 
because  the  supply  of  steam  is  exhausted. 


PREPARATION    OF    COAL 


49 


By  a  new  provision  of  the  State  Mining  Law  every  operator 
of  a  coal  mine  must  maintain  a  suitable  and  sanitary  washroom  for 
the  use  of  employes.     Fig.  30  shows  the  interior  of  the  wash-house 


Fig.    30.     Interior    of    Wash    House 

at  the  Hart-Williams  mine.     This  wash-house,  which  was  built  sev 
eral  years  before  the  new  law  was  passed,  has  been  much  used  by  the 
employes.      The  operators  state   that   they   arc   able   to  get  a   better 
class  of  labor  on  account  of  it. 

Table   L5. — Surface  jtlnnl  equipment 


No  loading 
tracks  beneath 
tipple 

T3 
CD 
J-  CD 

Boilers 

Electric 
generators 

Air  com- 
pressors 

6 

3^ 

<d   v 

2  a  % 

v   cd  " 

<  to  a 

No. 

£ 

W 

+-> 
'o 
> 

6 

£  a * 

a  S  3 

!fl  S  «  h 

^  c  oj  c 

50 

51 

52 

53 

4 
4 
4 
3 
3 
2 
4 
4 
4 
8 
4 
4 
6 
3 
8 

55 
60 
90 
45 
30 
40 
60 
55 
55 
90 
75 
100 
75 
25 
75 

8 
6 
7 
6 
4 
8 
6 
2 
7 
8 
4 
9 
L2 
4 
4 

1500 
900 

1050 
400 
600 
800 
900 
565 

1050 
900 
750 

1350 

2000 
450 
500 

100 

100 

125 

130 

120 

110 

100 

120 

120 

125 

85 

90 

90 

90 

80 

150 
100 
300 

500 
258 

300 
200 

150 
300 
175 
150 

150 

265 

250 
300 
250 
275 

250 
250 
250 
250 
250 
250 
250 

250 

2 

3 

3 

1 

'2 
2 

80 
100 

160 

54.  . 

55.. 

70 

56 

57 

58 

59 

60 

62 

'85 

63 

65 

64 

65 

PUBLICATIONS  OF  THE  ILLINOIS  COAL  MINING 
INVESTIGATIONS 


Bulletin  1. 

Bulletin  2. 

Bulletin  3. 

Bulletin  4. 


Bulletin  5. 

Bulletin  6. 

Bulletin  7. 

Bulletin  8. 


Preliminary  Keport  on  Organization  and  Method  of 
Investigations,  1913. 

Coal  Mining  Practice  in  District  VIII  (Danville), 
by  S.  O.  Andros,  1914. 

A  Chemical  Study  of  Illinois  Coals,  by  Prof.  S.  W. 
Parr,  1914. 

Coal  Mining  Practice  in  District  VII  (Mines  in  bed  6 
in  Bond,  Clinton,  Christian,  Macoupin,  Madison, 
Marion,  Montgomery,  Moultrie,  Perry,  Kandolph, 
St.  Clair,  Sangamon,  Shelby  and  Washington 
counties),  by  S.  O.  Andros,  1914. 

Coal  Mining  Practice  in  District  I  (Longwall),  by 
S.  0.  Andros,  1914. 

Coal  Mining  Practice  in  District  V  (Mines  in  bed  5 
in  Saline  and  Gallatin  counties),  by  S.  O. 
Andros,  1914. 

Coal  Mining  Practice  in  District  II  (Mines  in  bed  2 
in  Jackson  county),  by  S.  O.  Andros,  1914. 

Coal  Mining  Practice  in  District  VI  (Mines  in  bed  6 
in  Franklin,  Jackson,  Perry  and  Williamson  coun- 
ties), by  S.  O.  Andros,  1914. 


